Thickened bleach compositions possess a number of advantages over unthickened bleach compositions. The more viscous, thickened solutions adhere to vertical and inclined surfaces for a longer period of time as compared to the unthickened solutions. Consequently the bleaching or disinfectant activity of the thickened compositions is more effective on the intended areas.
To provide a thickened hypochlorite composition having an acceptable shelf-life, the rate of decomposition of alkali metal hypochlorite as well as the phase behavior of the composition must be considered. As known, alkali metal hypochlorite degradation may be illustrated by the following equation: EQU NaOCl.revreaction.NaCl+1/2 O.sub.2
Many conventional thickening agents accelerate the degradation of the hypochlorite and thus are problematic for use in hypochlorite compositions. Also, the inclusion of conventional thickening agents and surfactants is difficult because the resulting hypochlorite composition has a tendency to separate into two or more phases, particularly at elevated temperatures. Many thickening agents are themselves unstable in the presence of an alkali metal hypochlorite. Thus, achieving sufficient viscosity in hypochlorite compositions by conventional agents and additives in addition to providing a hypochlorite composition having acceptable stability is difficult.
Alternative hypochlorite compositions providing sufficient viscosity as well as an acceptable shelf-life (i.e. stability) are needed.